ssl/d1_srvr.c

   1 /* ssl/d1_srvr.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1999-2007 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include "ssl_locl.h"
 118 #include <openssl/buffer.h>
 119 #include <openssl/rand.h>
 120 #include <openssl/objects.h>
 121 #include <openssl/evp.h>
 122 #include <openssl/x509.h>
 123 #include <openssl/md5.h>
 124 #include <openssl/bn.h>
 125 #ifndef OPENSSL_NO_DH
 126 # include <openssl/dh.h>
 127 #endif
 128
 129 static const SSL_METHOD *dtls1_get_server_method(int ver);
 130 static int dtls1_send_hello_verify_request(SSL *s);
 131
 132 static const SSL_METHOD *dtls1_get_server_method(int ver)
 133 {
 134     if (ver == DTLS_ANY_VERSION)
 135         return DTLS_server_method();
 136     else if (ver == DTLS1_VERSION)
 137         return DTLSv1_server_method();
 138     else if (ver == DTLS1_2_VERSION)
 139         return DTLSv1_2_server_method();
 140     else
 141         return NULL;
 142 }
 143
 144 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
 145                           DTLSv1_server_method,
 146                           dtls1_accept,
 147                           ssl_undefined_function,
 148                           dtls1_get_server_method, DTLSv1_enc_data)
 149
 150 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
 151                           DTLSv1_2_server_method,
 152                           dtls1_accept,
 153                           ssl_undefined_function,
 154                           dtls1_get_server_method, DTLSv1_2_enc_data)
 155
 156 IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
 157                           DTLS_server_method,
 158                           dtls1_accept,
 159                           ssl_undefined_function,
 160                           dtls1_get_server_method, DTLSv1_2_enc_data)
 161
 162 int dtls1_accept(SSL *s)
 163 {
 164     BUF_MEM *buf;
 165     unsigned long Time = (unsigned long)time(NULL);
 166     void (*cb) (const SSL *ssl, int type, int val) = NULL;
 167     unsigned long alg_k;
 168     int ret = -1;
 169     int new_state, state, skip = 0;
 170     int listen;
 171 #ifndef OPENSSL_NO_SCTP
 172     unsigned char sctpauthkey[64];
 173     char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
 174 #endif
 175
 176     RAND_add(&Time, sizeof(Time), 0);
 177     ERR_clear_error();
 178     clear_sys_error();
 179
 180     if (s->info_callback != NULL)
 181         cb = s->info_callback;
 182     else if (s->ctx->info_callback != NULL)
 183         cb = s->ctx->info_callback;
 184
 185     listen = s->d1->listen;
 186
 187     /* init things to blank */
 188     s->in_handshake++;
 189     if (!SSL_in_init(s) || SSL_in_before(s))
 190         SSL_clear(s);
 191
 192     s->d1->listen = listen;
 193 #ifndef OPENSSL_NO_SCTP
 194     /*
 195      * Notify SCTP BIO socket to enter handshake mode and prevent stream
 196      * identifier other than 0. Will be ignored if no SCTP is used.
 197      */
 198     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 199              s->in_handshake, NULL);
 200 #endif
 201
 202     if (s->cert == NULL) {
 203         SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
 204         return (-1);
 205     }
 206 #ifndef OPENSSL_NO_HEARTBEATS
 207     /*
 208      * If we're awaiting a HeartbeatResponse, pretend we already got and
 209      * don't await it anymore, because Heartbeats don't make sense during
 210      * handshakes anyway.
 211      */
 212     if (s->tlsext_hb_pending) {
 213         dtls1_stop_timer(s);
 214         s->tlsext_hb_pending = 0;
 215         s->tlsext_hb_seq++;
 216     }
 217 #endif
 218
 219     for (;;) {
 220         state = s->state;
 221
 222         switch (s->state) {
 223         case SSL_ST_RENEGOTIATE:
 224             s->renegotiate = 1;
 225             /* s->state=SSL_ST_ACCEPT; */
 226
 227         case SSL_ST_BEFORE:
 228         case SSL_ST_ACCEPT:
 229         case SSL_ST_BEFORE | SSL_ST_ACCEPT:
 230         case SSL_ST_OK | SSL_ST_ACCEPT:
 231
 232             s->server = 1;
 233             if (cb != NULL)
 234                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 235
 236             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
 237                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 238                 return -1;
 239             }
 240             s->type = SSL_ST_ACCEPT;
 241
 242             if (s->init_buf == NULL) {
 243                 if ((buf = BUF_MEM_new()) == NULL) {
 244                     ret = -1;
 245                     s->state = SSL_ST_ERR;
 246                     goto end;
 247                 }
 248                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
 249                     BUF_MEM_free(buf);
 250                     ret = -1;
 251                     s->state = SSL_ST_ERR;
 252                     goto end;
 253                 }
 254                 s->init_buf = buf;
 255             }
 256
 257             if (!ssl3_setup_buffers(s)) {
 258                 ret = -1;
 259                 s->state = SSL_ST_ERR;
 260                 goto end;
 261             }
 262
 263             s->init_num = 0;
 264             s->d1->change_cipher_spec_ok = 0;
 265             /*
 266              * Should have been reset by ssl3_get_finished, too.
 267              */
 268             s->s3->change_cipher_spec = 0;
 269
 270             if (s->state != SSL_ST_RENEGOTIATE) {
 271                 /*
 272                  * Ok, we now need to push on a buffering BIO so that the
 273                  * output is sent in a way that TCP likes :-) ...but not with
 274                  * SCTP :-)
 275                  */
 276 #ifndef OPENSSL_NO_SCTP
 277                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
 278 #endif
 279                     if (!ssl_init_wbio_buffer(s, 1)) {
 280                         ret = -1;
 281                         s->state = SSL_ST_ERR;
 282                         goto end;
 283                     }
 284
 285                 ssl3_init_finished_mac(s);
 286                 s->state = SSL3_ST_SR_CLNT_HELLO_A;
 287                 s->ctx->stats.sess_accept++;
 288             } else if (!s->s3->send_connection_binding &&
 289                        !(s->options &
 290                          SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
 291                 /*
 292                  * Server attempting to renegotiate with client that doesn't
 293                  * support secure renegotiation.
 294                  */
 295                 SSLerr(SSL_F_DTLS1_ACCEPT,
 296                        SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
 297                 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
 298                 ret = -1;
 299                 s->state = SSL_ST_ERR;
 300                 goto end;
 301             } else {
 302                 /*
 303                  * s->state == SSL_ST_RENEGOTIATE, we will just send a
 304                  * HelloRequest
 305                  */
 306                 s->ctx->stats.sess_accept_renegotiate++;
 307                 s->state = SSL3_ST_SW_HELLO_REQ_A;
 308             }
 309
 310             break;
 311
 312         case SSL3_ST_SW_HELLO_REQ_A:
 313         case SSL3_ST_SW_HELLO_REQ_B:
 314
 315             s->shutdown = 0;
 316             dtls1_clear_sent_buffer(s);
 317             dtls1_start_timer(s);
 318             ret = ssl3_send_hello_request(s);
 319             if (ret <= 0)
 320                 goto end;
 321             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 322             s->state = SSL3_ST_SW_FLUSH;
 323             s->init_num = 0;
 324
 325             ssl3_init_finished_mac(s);
 326             break;
 327
 328         case SSL3_ST_SW_HELLO_REQ_C:
 329             s->state = SSL_ST_OK;
 330             break;
 331
 332         case SSL3_ST_SR_CLNT_HELLO_A:
 333         case SSL3_ST_SR_CLNT_HELLO_B:
 334         case SSL3_ST_SR_CLNT_HELLO_C:
 335
 336             s->shutdown = 0;
 337             ret = ssl3_get_client_hello(s);
 338             if (ret <= 0)
 339                 goto end;
 340             dtls1_stop_timer(s);
 341
 342             if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
 343                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
 344             else
 345                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
 346
 347             s->init_num = 0;
 348
 349             /*
 350              * Reflect ClientHello sequence to remain stateless while
 351              * listening
 352              */
 353             if (listen) {
 354                 memcpy(s->s3->write_sequence, s->s3->read_sequence,
 355                        sizeof(s->s3->write_sequence));
 356             }
 357
 358             /* If we're just listening, stop here */
 359             if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
 360                 ret = 2;
 361                 s->d1->listen = 0;
 362                 /*
 363                  * Set expected sequence numbers to continue the handshake.
 364                  */
 365                 s->d1->handshake_read_seq = 2;
 366                 s->d1->handshake_write_seq = 1;
 367                 s->d1->next_handshake_write_seq = 1;
 368                 goto end;
 369             }
 370
 371             break;
 372
 373         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
 374         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
 375
 376             ret = dtls1_send_hello_verify_request(s);
 377             if (ret <= 0)
 378                 goto end;
 379             s->state = SSL3_ST_SW_FLUSH;
 380             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
 381
 382             /* HelloVerifyRequest resets Finished MAC */
 383             if (s->version != DTLS1_BAD_VER)
 384                 ssl3_init_finished_mac(s);
 385             break;
 386
 387 #ifndef OPENSSL_NO_SCTP
 388         case DTLS1_SCTP_ST_SR_READ_SOCK:
 389
 390             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
 391                 s->s3->in_read_app_data = 2;
 392                 s->rwstate = SSL_READING;
 393                 BIO_clear_retry_flags(SSL_get_rbio(s));
 394                 BIO_set_retry_read(SSL_get_rbio(s));
 395                 ret = -1;
 396                 goto end;
 397             }
 398
 399             s->state = SSL3_ST_SR_FINISHED_A;
 400             break;
 401
 402         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
 403             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
 404             if (ret < 0)
 405                 goto end;
 406
 407             if (ret == 0) {
 408                 if (s->d1->next_state != SSL_ST_OK) {
 409                     s->s3->in_read_app_data = 2;
 410                     s->rwstate = SSL_READING;
 411                     BIO_clear_retry_flags(SSL_get_rbio(s));
 412                     BIO_set_retry_read(SSL_get_rbio(s));
 413                     ret = -1;
 414                     goto end;
 415                 }
 416             }
 417
 418             s->state = s->d1->next_state;
 419             break;
 420 #endif
 421
 422         case SSL3_ST_SW_SRVR_HELLO_A:
 423         case SSL3_ST_SW_SRVR_HELLO_B:
 424             s->renegotiate = 2;
 425             dtls1_start_timer(s);
 426             ret = ssl3_send_server_hello(s);
 427             if (ret <= 0)
 428                 goto end;
 429
 430             if (s->hit) {
 431 #ifndef OPENSSL_NO_SCTP
 432                 /*
 433                  * Add new shared key for SCTP-Auth, will be ignored if no
 434                  * SCTP used.
 435                  */
 436                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 437                          DTLS1_SCTP_AUTH_LABEL);
 438
 439                 if (SSL_export_keying_material(s, sctpauthkey,
 440                         sizeof(sctpauthkey), labelbuffer,
 441                         sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 442                     ret = -1;
 443                     s->state = SSL_ST_ERR;
 444                     goto end;
 445                 }
 446
 447                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 448                          sizeof(sctpauthkey), sctpauthkey);
 449 #endif
 450 #ifndef OPENSSL_NO_TLSEXT
 451                 if (s->tlsext_ticket_expected)
 452                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
 453                 else
 454                     s->state = SSL3_ST_SW_CHANGE_A;
 455 #else
 456                 s->state = SSL3_ST_SW_CHANGE_A;
 457 #endif
 458             } else
 459                 s->state = SSL3_ST_SW_CERT_A;
 460             s->init_num = 0;
 461             break;
 462
 463         case SSL3_ST_SW_CERT_A:
 464         case SSL3_ST_SW_CERT_B:
 465             /* Check if it is anon DH or normal PSK */
 466             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
 467                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 468                 dtls1_start_timer(s);
 469                 ret = ssl3_send_server_certificate(s);
 470                 if (ret <= 0)
 471                     goto end;
 472 #ifndef OPENSSL_NO_TLSEXT
 473                 if (s->tlsext_status_expected)
 474                     s->state = SSL3_ST_SW_CERT_STATUS_A;
 475                 else
 476                     s->state = SSL3_ST_SW_KEY_EXCH_A;
 477             } else {
 478                 skip = 1;
 479                 s->state = SSL3_ST_SW_KEY_EXCH_A;
 480             }
 481 #else
 482             } else
 483                 skip = 1;
 484
 485             s->state = SSL3_ST_SW_KEY_EXCH_A;
 486 #endif
 487             s->init_num = 0;
 488             break;
 489
 490         case SSL3_ST_SW_KEY_EXCH_A:
 491         case SSL3_ST_SW_KEY_EXCH_B:
 492             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 493
 494             /*
 495              * clear this, it may get reset by
 496              * send_server_key_exchange
 497              */
 498             s->s3->tmp.use_rsa_tmp = 0;
 499
 500             /*
 501              * only send if a DH key exchange or RSA but we have a sign only
 502              * certificate
 503              */
 504             if (0
 505                 /*
 506                  * PSK: send ServerKeyExchange if PSK identity hint if
 507                  * provided
 508                  */
 509 #ifndef OPENSSL_NO_PSK
 510                 || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
 511 #endif
 512                 || (alg_k & SSL_kDHE)
 513                 || (alg_k & SSL_kEECDH)
 514                 || ((alg_k & SSL_kRSA)
 515                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
 516                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
 517                             && EVP_PKEY_size(s->cert->pkeys
 518                                              [SSL_PKEY_RSA_ENC].privatekey) *
 519                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
 520                         )
 521                     )
 522                 )
 523                 ) {
 524                 dtls1_start_timer(s);
 525                 ret = ssl3_send_server_key_exchange(s);
 526                 if (ret <= 0)
 527                     goto end;
 528             } else
 529                 skip = 1;
 530
 531             s->state = SSL3_ST_SW_CERT_REQ_A;
 532             s->init_num = 0;
 533             break;
 534
 535         case SSL3_ST_SW_CERT_REQ_A:
 536         case SSL3_ST_SW_CERT_REQ_B:
 537             if (                /* don't request cert unless asked for it: */
 538                    !(s->verify_mode & SSL_VERIFY_PEER) ||
 539                    /*
 540                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
 541                     * during re-negotiation:
 542                     */
 543                    ((s->session->peer != NULL) &&
 544                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
 545                    /*
 546                     * never request cert in anonymous ciphersuites (see
 547                     * section "Certificate request" in SSL 3 drafts and in
 548                     * RFC 2246):
 549                     */
 550                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
 551                     /*
 552                      * ... except when the application insists on
 553                      * verification (against the specs, but s3_clnt.c accepts
 554                      * this for SSL 3)
 555                      */
 556                     !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
 557                    /*
 558                     * never request cert in Kerberos ciphersuites
 559                     */
 560                    (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
 561                    /*
 562                     * With normal PSK Certificates and Certificate Requests
 563                     * are omitted
 564                     */
 565                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
 566                 /* no cert request */
 567                 skip = 1;
 568                 s->s3->tmp.cert_request = 0;
 569                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 570 #ifndef OPENSSL_NO_SCTP
 571                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 572                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 573                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 574                 }
 575 #endif
 576             } else {
 577                 s->s3->tmp.cert_request = 1;
 578                 dtls1_start_timer(s);
 579                 ret = ssl3_send_certificate_request(s);
 580                 if (ret <= 0)
 581                     goto end;
 582 #ifndef NETSCAPE_HANG_BUG
 583                 s->state = SSL3_ST_SW_SRVR_DONE_A;
 584 # ifndef OPENSSL_NO_SCTP
 585                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 586                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
 587                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 588                 }
 589 # endif
 590 #else
 591                 s->state = SSL3_ST_SW_FLUSH;
 592                 s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 593 # ifndef OPENSSL_NO_SCTP
 594                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 595                     s->d1->next_state = s->s3->tmp.next_state;
 596                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 597                 }
 598 # endif
 599 #endif
 600                 s->init_num = 0;
 601             }
 602             break;
 603
 604         case SSL3_ST_SW_SRVR_DONE_A:
 605         case SSL3_ST_SW_SRVR_DONE_B:
 606             dtls1_start_timer(s);
 607             ret = ssl3_send_server_done(s);
 608             if (ret <= 0)
 609                 goto end;
 610             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
 611             s->state = SSL3_ST_SW_FLUSH;
 612             s->init_num = 0;
 613             break;
 614
 615         case SSL3_ST_SW_FLUSH:
 616             s->rwstate = SSL_WRITING;
 617             if (BIO_flush(s->wbio) <= 0) {
 618                 /*
 619                  * If the write error was fatal, stop trying
 620                  */
 621                 if (!BIO_should_retry(s->wbio)) {
 622                     s->rwstate = SSL_NOTHING;
 623                     s->state = s->s3->tmp.next_state;
 624                 }
 625
 626                 ret = -1;
 627                 goto end;
 628             }
 629             s->rwstate = SSL_NOTHING;
 630             s->state = s->s3->tmp.next_state;
 631             break;
 632
 633         case SSL3_ST_SR_CERT_A:
 634         case SSL3_ST_SR_CERT_B:
 635             if (s->s3->tmp.cert_request) {
 636                 ret = ssl3_get_client_certificate(s);
 637                 if (ret <= 0)
 638                     goto end;
 639             }
 640             s->init_num = 0;
 641             s->state = SSL3_ST_SR_KEY_EXCH_A;
 642             break;
 643
 644         case SSL3_ST_SR_KEY_EXCH_A:
 645         case SSL3_ST_SR_KEY_EXCH_B:
 646             ret = ssl3_get_client_key_exchange(s);
 647             if (ret <= 0)
 648                 goto end;
 649 #ifndef OPENSSL_NO_SCTP
 650             /*
 651              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
 652              * used.
 653              */
 654             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
 655                      DTLS1_SCTP_AUTH_LABEL);
 656
 657             if (SSL_export_keying_material(s, sctpauthkey,
 658                                        sizeof(sctpauthkey), labelbuffer,
 659                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
 660                 ret = -1;
 661                 s->state = SSL_ST_ERR;
 662                 goto end;
 663             }
 664
 665             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
 666                      sizeof(sctpauthkey), sctpauthkey);
 667 #endif
 668
 669             s->state = SSL3_ST_SR_CERT_VRFY_A;
 670             s->init_num = 0;
 671
 672             if (ret == 2) {
 673                 /*
 674                  * For the ECDH ciphersuites when the client sends its ECDH
 675                  * pub key in a certificate, the CertificateVerify message is
 676                  * not sent.
 677                  */
 678                 s->state = SSL3_ST_SR_FINISHED_A;
 679                 s->init_num = 0;
 680             } else if (SSL_USE_SIGALGS(s)) {
 681                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 682                 s->init_num = 0;
 683                 if (!s->session->peer)
 684                     break;
 685                 /*
 686                  * For sigalgs freeze the handshake buffer at this point and
 687                  * digest cached records.
 688                  */
 689                 if (!s->s3->handshake_buffer) {
 690                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
 691                     s->state = SSL_ST_ERR;
 692                     return -1;
 693                 }
 694                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
 695                 if (!ssl3_digest_cached_records(s)) {
 696                     s->state = SSL_ST_ERR;
 697                     return -1;
 698                 }
 699             } else {
 700                 s->state = SSL3_ST_SR_CERT_VRFY_A;
 701                 s->init_num = 0;
 702
 703                 /*
 704                  * We need to get hashes here so if there is a client cert,
 705                  * it can be verified
 706                  */
 707                 s->method->ssl3_enc->cert_verify_mac(s,
 708                                                      NID_md5,
 709                                                      &(s->s3->
 710                                                        tmp.cert_verify_md
 711                                                        [0]));
 712                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
 713                                                      &(s->s3->
 714                                                        tmp.cert_verify_md
 715                                                        [MD5_DIGEST_LENGTH]));
 716             }
 717             break;
 718
 719         case SSL3_ST_SR_CERT_VRFY_A:
 720         case SSL3_ST_SR_CERT_VRFY_B:
 721             ret = ssl3_get_cert_verify(s);
 722             if (ret <= 0)
 723                 goto end;
 724 #ifndef OPENSSL_NO_SCTP
 725             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
 726                 state == SSL_ST_RENEGOTIATE)
 727                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
 728             else
 729 #endif
 730                 s->state = SSL3_ST_SR_FINISHED_A;
 731             s->init_num = 0;
 732             break;
 733
 734         case SSL3_ST_SR_FINISHED_A:
 735         case SSL3_ST_SR_FINISHED_B:
 736             /*
 737              * Enable CCS. Receiving a CCS clears the flag, so make
 738              * sure not to re-enable it to ban duplicates. This *should* be the
 739              * first time we have received one - but we check anyway to be
 740              * cautious.
 741              * s->s3->change_cipher_spec is set when a CCS is
 742              * processed in d1_pkt.c, and remains set until
 743              * the client's Finished message is read.
 744              */
 745             if (!s->s3->change_cipher_spec)
 746                 s->d1->change_cipher_spec_ok = 1;
 747             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
 748                                     SSL3_ST_SR_FINISHED_B);
 749             if (ret <= 0)
 750                 goto end;
 751             dtls1_stop_timer(s);
 752             if (s->hit)
 753                 s->state = SSL_ST_OK;
 754 #ifndef OPENSSL_NO_TLSEXT
 755             else if (s->tlsext_ticket_expected)
 756                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
 757 #endif
 758             else
 759                 s->state = SSL3_ST_SW_CHANGE_A;
 760             s->init_num = 0;
 761             break;
 762
 763 #ifndef OPENSSL_NO_TLSEXT
 764         case SSL3_ST_SW_SESSION_TICKET_A:
 765         case SSL3_ST_SW_SESSION_TICKET_B:
 766             ret = ssl3_send_newsession_ticket(s);
 767             if (ret <= 0)
 768                 goto end;
 769             s->state = SSL3_ST_SW_CHANGE_A;
 770             s->init_num = 0;
 771             break;
 772
 773         case SSL3_ST_SW_CERT_STATUS_A:
 774         case SSL3_ST_SW_CERT_STATUS_B:
 775             ret = ssl3_send_cert_status(s);
 776             if (ret <= 0)
 777                 goto end;
 778             s->state = SSL3_ST_SW_KEY_EXCH_A;
 779             s->init_num = 0;
 780             break;
 781
 782 #endif
 783
 784         case SSL3_ST_SW_CHANGE_A:
 785         case SSL3_ST_SW_CHANGE_B:
 786
 787             s->session->cipher = s->s3->tmp.new_cipher;
 788             if (!s->method->ssl3_enc->setup_key_block(s)) {
 789                 ret = -1;
 790                 s->state = SSL_ST_ERR;
 791                 goto end;
 792             }
 793
 794             ret = dtls1_send_change_cipher_spec(s,
 795                                                 SSL3_ST_SW_CHANGE_A,
 796                                                 SSL3_ST_SW_CHANGE_B);
 797
 798             if (ret <= 0)
 799                 goto end;
 800
 801 #ifndef OPENSSL_NO_SCTP
 802             if (!s->hit) {
 803                 /*
 804                  * Change to new shared key of SCTP-Auth, will be ignored if
 805                  * no SCTP used.
 806                  */
 807                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 808                          0, NULL);
 809             }
 810 #endif
 811
 812             s->state = SSL3_ST_SW_FINISHED_A;
 813             s->init_num = 0;
 814
 815             if (!s->method->ssl3_enc->change_cipher_state(s,
 816                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
 817             {
 818                 ret = -1;
 819                 s->state = SSL_ST_ERR;
 820                 goto end;
 821             }
 822
 823             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
 824             break;
 825
 826         case SSL3_ST_SW_FINISHED_A:
 827         case SSL3_ST_SW_FINISHED_B:
 828             ret = ssl3_send_finished(s,
 829                                      SSL3_ST_SW_FINISHED_A,
 830                                      SSL3_ST_SW_FINISHED_B,
 831                                      s->method->
 832                                      ssl3_enc->server_finished_label,
 833                                      s->method->
 834                                      ssl3_enc->server_finished_label_len);
 835             if (ret <= 0)
 836                 goto end;
 837             s->state = SSL3_ST_SW_FLUSH;
 838             if (s->hit) {
 839                 s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
 840
 841 #ifndef OPENSSL_NO_SCTP
 842                 /*
 843                  * Change to new shared key of SCTP-Auth, will be ignored if
 844                  * no SCTP used.
 845                  */
 846                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
 847                          0, NULL);
 848 #endif
 849             } else {
 850                 s->s3->tmp.next_state = SSL_ST_OK;
 851 #ifndef OPENSSL_NO_SCTP
 852                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
 853                     s->d1->next_state = s->s3->tmp.next_state;
 854                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
 855                 }
 856 #endif
 857             }
 858             s->init_num = 0;
 859             break;
 860
 861         case SSL_ST_OK:
 862             /* clean a few things up */
 863             ssl3_cleanup_key_block(s);
 864
 865 #if 0
 866             BUF_MEM_free(s->init_buf);
 867             s->init_buf = NULL;
 868 #endif
 869
 870             /* remove buffering on output */
 871             ssl_free_wbio_buffer(s);
 872
 873             s->init_num = 0;
 874
 875             if (s->renegotiate == 2) { /* skipped if we just sent a
 876                                         * HelloRequest */
 877                 s->renegotiate = 0;
 878                 s->new_session = 0;
 879
 880                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
 881
 882                 s->ctx->stats.sess_accept_good++;
 883                 /* s->server=1; */
 884                 s->handshake_func = dtls1_accept;
 885
 886                 if (cb != NULL)
 887                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
 888             }
 889
 890             ret = 1;
 891
 892             /* done handshaking, next message is client hello */
 893             s->d1->handshake_read_seq = 0;
 894             /* next message is server hello */
 895             s->d1->handshake_write_seq = 0;
 896             s->d1->next_handshake_write_seq = 0;
 897             dtls1_clear_received_buffer(s);
 898             goto end;
 899             /* break; */
 900
 901         case SSL_ST_ERR:
 902         default:
 903             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
 904             ret = -1;
 905             goto end;
 906             /* break; */
 907         }
 908
 909         if (!s->s3->tmp.reuse_message && !skip) {
 910             if (s->debug) {
 911                 if ((ret = BIO_flush(s->wbio)) <= 0)
 912                     goto end;
 913             }
 914
 915             if ((cb != NULL) && (s->state != state)) {
 916                 new_state = s->state;
 917                 s->state = state;
 918                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
 919                 s->state = new_state;
 920             }
 921         }
 922         skip = 0;
 923     }
 924  end:
 925     /* BIO_flush(s->wbio); */
 926
 927     s->in_handshake--;
 928 #ifndef OPENSSL_NO_SCTP
 929     /*
 930      * Notify SCTP BIO socket to leave handshake mode and prevent stream
 931      * identifier other than 0. Will be ignored if no SCTP is used.
 932      */
 933     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
 934              s->in_handshake, NULL);
 935 #endif
 936
 937     if (cb != NULL)
 938         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 939     return (ret);
 940 }
 941
 942 int dtls1_send_hello_verify_request(SSL *s)
 943 {
 944     unsigned int msg_len;
 945     unsigned char *msg, *buf, *p;
 946
 947     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
 948         buf = (unsigned char *)s->init_buf->data;
 949
 950         msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
 951         /* Always use DTLS 1.0 version: see RFC 6347 */
 952         *(p++) = DTLS1_VERSION >> 8;
 953         *(p++) = DTLS1_VERSION & 0xFF;
 954
 955         if (s->ctx->app_gen_cookie_cb == NULL ||
 956             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
 957                                       &(s->d1->cookie_len)) == 0) {
 958             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
 959                    ERR_R_INTERNAL_ERROR);
 960             s->state = SSL_ST_ERR;
 961             return 0;
 962         }
 963
 964         *(p++) = (unsigned char)s->d1->cookie_len;
 965         memcpy(p, s->d1->cookie, s->d1->cookie_len);
 966         p += s->d1->cookie_len;
 967         msg_len = p - msg;
 968
 969         dtls1_set_message_header(s, buf,
 970                                  DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
 971                                  msg_len);
 972
 973         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
 974         /* number of bytes to write */
 975         s->init_num = p - buf;
 976         s->init_off = 0;
 977     }
 978
 979     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
 980     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
 981 }